Each aircraft, if it is to fly safely, must have its center of gravity set correctly. It doesn’t matter whether it is real or model. On a real plane, we see this in the distribution of passengers’ cargo and luggage. Modelers in models solve this by sliding in the models, most often batteries, or inserting additional weights. Why it is important to have a balanced plane knows every modeler, advanced, even beginners.

Setting the actual center of gravity of the aircraft as calculated as possible is important before the first flight of the model aircraft. Longitudinal as well as transverse center of gravity. It goes without saying that you do not exceed the All-Up Weight. Therefore, each modeler tries to move in the aircraft what can be shifted, and then to prove the least additional weight.

As the weight increases, the wing loading increases. This term indicates how much each wing of your model must bear. We will not deal with this here, it is important to maintain the maximum weight of the aircraft as defined by the manufacturer or constructor. In general, however, it is better to have a minimum of ballast on an aircraft than a poorly balanced model. However, let us return with a little theory to the focus. How it actually works and we start with a longitudinal balance …

Aircraft balancing

A nose-heavy aircraft, an aircraft that has a center of gravity very forward, tends to tilt its nose to the ground and drop sharply.

A tail-heavy aircraft, that is, an aircraft with a center of gravity at the rear, rises during the flight, raises the nose up, losing speed and starting to fall.

A properly balanced aircraft sinks slightly evenly over the flight, does not stagger, spin, or nose down.

A laterally unbalanced aircraft has one wing heavier than the other, thus the longitudinal axis is offset to the side. This can be partially compensated by the wings, but not for each flight mode.


We have developed the CG GURU – electronic aircraft balancer. It is an electronic device for safe, simple and very precise adjustment of the center of gravity of aircraft models with a maximum weight of 10, 20 and 50 kg. With CG GURU we can balance aircraft with or without undercarriage, delta gliders or self-wings. CG GURU communicates in English and other seven languages.

How does it work.

To set the center of gravity of the aircraft model using CG GURU, you can connect any device with a web browser via WiFi. It can be a smartphone or a laptop. You don’t need to install any application, just a web browser such as CHROME, SAFARI, or FIREFOX. The balancer creates its own WiFi A.M.E., you don’t need an internet connection! You select the type of model, enter the required dimensions of the aircraft model from the nose, illustrative pictures will help you. You place the model either directly on the sensors with wheels, or we have a special base for models without a chassis. Depending on the weight distribution, you can see the difference between the desired center of gravity and the actual center of gravity of the aircraft model in the BASIC model on the device display.

By moving the components in the model, or by proving the additional weight, you will achieve a match between the required and the actual center of gravity of your model. The display changes as you move the devices or document the weights. Everything runs in real time online.

The classical balancing of models is often not a simple matter. We have to put the model, swing it, hang it, which can lead to “accidents” already in the workshop. This was also taken into account in the development of CG GURU. We have eliminated the necessity in many cases to assemble the model from sensors, to add additional weight to the model and to put the model on the stand or sensors again. To minimize model manipulation, we can calculate the weight of the extra weight in the advanced CG GURU ADVANCE model. Simply enter the distance of the extra load space and CG GURU ADVANCE calculates the weight of the extra weight to accurately balance the model. So we are balancing the model once.

Lateral model balancing

The transverse balancing of the model, ie if we have one wing heavier than the other, is quite underestimated and the truth is not as critical as the longitudinal balance. However, “squeezing” the wings will only level the aircraft at a given speed.

When changing flight mode, speed, or aerobatic elements, the most accurate transverse balance is important. All CG GURU models compare the mass pressures of the main undercarriage wheels or the wing weights on the stand directly and calculate the lateral axis shift to the side. So on the other hand we show slow weights, the display immediately shows the current state until the model is laterally balanced.

Something extra

We have already mentioned the overall weight of the model and its impact on the area load. All CG GURU models display the total weight of the model. At the same time, they display the mass pressures on the main undercarriage wheels, helping the designer to select the “appropriate fit” for the model undercarriage.

At the end

It is important to realize that the aircraft a little heavy on the nose will fly relatively well, heavy on the tail is almost unmanageable. If one thinks that he will compensate for the misalignment by trimming the rudders, he only achieves that the model will fly straight at only one speed. Aircraft will become totally unstable at a different speed, and I’m not talking about any other flight mode at all. At that time, the aircraft can become unmanageable. An unbalanced aircraft can only fly in a very small range of speeds, with the risk of jet tearing and subsequent aircraft crashes. Although a smaller model can be “finger balanced”, other balancing methods can be used. Compared to all, CG CGURU gives you balancing accuracy, simplicity, speed and, last but not least, safety when working with the model in the workshop.